Omental cysts are rare, benign intraabdominal lesions primarily identified in children under the age of 10 years (68%), although they have been reported in adults. These are most commonly serous-filled cysts encased by a fibrous wall, lined by cuboidal epithelium. Omental cysts are likely congenital and related to lymphangiomas that occur elsewhere in the body. The majority of the cysts are solitary and may be unilocular or multilocular on imaging. The cysts may be filled with serous, chylous, hemorrhagic, or infected fluid.

They most frequently present as chronic abdominal distension. They less frequently present as an abdominal mass with pain, fatigue, or pallor; in these cases, surgical evaluation and cyst resection can be undertaken at the discretion of the patient / family. Omental cysts may rarely present as an acute abdomen requiring surgery or an enlarging cyst that compromises the respiratory or urinary system.

Complications from an enlarging omental cyst may include bleeding, infection, rupture, and torsion. In these rare cases, emergent complete surgical excision is warranted.